[TeMPOraL]

Everything except HTML and charts will be easy - after all, if something can be represented as or drawn with plain text, Emacs is probably the best tool for working with it. HTML has some half-decent previewers available, but those are essentially text browsers in elisp. Unfortunately, painting arbitrary images gets unwieldy with Emacs. You can get away with ASCII column charts, but forget scatter plots or sparklines. But for viewing that, I wouldn't mind an external application to put on another screen.